In the cutting of threads in a formed hole, a circular cylindrical tap has been used which usually has shallow threads at the end graduated into full threads as the threads progress upwardly in the tap body. The taps sometimes have axial slots in the threads to assist in the removal of chips cut by the threads on the tap. But chip removal has remained a problem and has resulted in a slowing of the tapping process and sometimes a jamming of the tap threads requiring a removal and reinsertion of the tap to clear the threads prior to finishing the hole.
It is an object of the present invention to provide a tap which can be used in a more rapid tapping action and one which will eliminate the chip problem by providing a chip removal structure adequate to eliminate any chip jamming which could cause defacing of the formed threads. It is a further object to provide a tap which can be utilized in a single pass even for relatively long holes. It is a further object to provide a tap which can be easily molded into its finished form.
Briefly, this is accomplished by providing a semi-circular tap body which, it has been found, will center itself perfectly in a hole and provide a clear channel for chips to fall clear of the tap and the hole.